Hot Rolled Annealed Hastelloy C276 Round Bar D5 - 350mm C276
Chemical Composition
Hastelloy C276, designated as UNS N10276 and W.Nr 2.4819, stands as
a premier nickel-chromium-molybdenum-tungsten alloy renowned for
its exceptional corrosion resistance and thermal stability. The hot
rolled annealed Hastelloy C276 round bar, available in diameters
ranging from 5mm to 350mm, combines precise chemical engineering
with advanced processing to meet the stringent demands of
high-corrosion industrial environments. This product integrates the
alloy’s inherent performance advantages with the enhanced ductility
and surface quality delivered by hot rolling and annealing, making
it a cornerstone material for critical applications across sectors.
Core Value: Chemical Composition of Hastelloy C276
The superior performance of Hastelloy C276 round bars originates
from its meticulously controlled chemical composition. Each element
is proportioned to synergistically enhance corrosion resistance,
mechanical strength, and processability, adhering to international
standards such as ASTM B574 and ISO 15156-3 (NACE MR 0175) . The
table below details the precise chemical composition ranges:
| Element | Content Range (%) | Key Function |
|---|
| Nickel (Ni) | Balance (≥57) | Serves as the alloy matrix, ensuring fundamental ductility and
chemical stability |
| Chromium (Cr) | 14.5 - 16.5 | Enhances oxidation resistance and defends against pitting/crevice
corrosion |
| Molybdenum (Mo) | 15.0 - 17.0 | Boosts resistance to reducing acids (e.g., sulfuric, hydrochloric)
and localized corrosion |
| Tungsten (W) | 3.0 - 4.5 | Complements molybdenum to strengthen chloride-induced corrosion
resistance |
| Iron (Fe) | 4.0 - 7.0 | Optimizes cost-efficiency while maintaining alloy integrity |
| Cobalt (Co) | ≤2.5 | Controlled to minimize potential environmental impact and maintain
performance |
| Carbon (C) | ≤0.02 (typical) | Prevents carbide precipitation during welding, preserving
intergranular corrosion resistance |
| Silicon (Si) | ≤0.08 | Reduces welding stress and avoids harmful oxide formation |
| Manganese (Mn) | ≤1.0 | Aids in deoxidation without compromising corrosion resistance |
| Vanadium (V) | ≤0.35 | Refines grain structure for improved mechanical properties |
| Phosphorus (P) | ≤0.03 | Limited to prevent brittleness and maintain weldability |
| Sulfur (S) | ≤0.03 | Minimized to avoid hot cracking during processing |
This composition creates a material uniquely resistant to both
oxidizing and reducing corrosive media—a rarity among industrial
alloys . The low carbon content is particularly critical for welded
applications, as it eliminates carbide precipitation in
heat-affected zones that would otherwise lead to intergranular
corrosion .
Product Specifications: Hot Rolled Annealed Finish
The hot rolled annealing process is pivotal to unlocking the
alloy’s full potential. After hot rolling to achieve the 5-350mm
diameter range, the round bars undergo annealing at approximately
1121°C (2250°F) followed by rapid cooling . This treatment delivers
three key benefits:
- Microstructural Uniformity: Eliminates residual stresses from hot
rolling and ensures a consistent, fine-grained structure across the
entire diameter.
- Enhanced Ductility: Annealed bars exhibit elongation rates up to
40% , facilitating fabrication processes like bending, forging, and
machining.
- Optimal Corrosion Resistance: The heat treatment maximizes the
alloy’s ability to resist pitting, crevice corrosion, and stress
corrosion cracking in chloride-rich environments .
In terms of dimensional accuracy, the bars comply with ASTM B575
standards, featuring tight diameter tolerances (typically ±0.5mm
for smaller diameters and ±1% for larger sizes) and a smooth
surface finish that reduces the need for post-purchase machining.
Mechanical & Physical Properties
The combination of chemical composition and annealing results in a
material with balanced mechanical strength and physical stability,
suitable for extreme operating conditions:
| Property | Metric Value | Imperial Value |
|---|
| Density | 8.89 g/cm³ | 0.321 lbs/in³ |
| Modulus of Elasticity | 205 GPa | 29.8 mpsi |
| Ultimate Tensile Strength | 842 MPa (annealed) | 122 ksi (annealed) |
| Yield Strength (0.2%) | 455 MPa (annealed) | 66 ksi (annealed) |
| Elongation | 40% (annealed) | 40% (annealed) |
| Thermal Conductivity | 9.8 W/(m·°C) | 67.9 Btu·in/(hr·ft²·°F) |
| Thermal Expansion (20-100°C) | 11.2 µm/(m·°C) | 6.2 µin/(in·°F) |
| Electrical Resistivity | 130 µΩ·cm | 51 µΩ·in |
Notably, the alloy maintains these properties across a wide
temperature range—resisting oxidation up to 649°C (1200°F) and
retaining strength in cryogenic conditions. Its non-magnetic nature
also makes it suitable for magnetic resonance imaging (MRI)
equipment components and other magnetically sensitive applications.
Industrial Applications
The versatility of hot rolled annealed Hastelloy C276 round bars
stems from their ability to perform in diverse harsh environments.
Key application areas include:
- Chemical Processing: Used for reactors, storage tanks, and piping
handling sulfuric acid, acetic acid, and chlorine gas . The alloy’s
resistance to both oxidizing and reducing acids makes it
indispensable for multi-step chemical production lines.
- Oil & Gas Industry: Deployed in offshore oil rigs, downhole
equipment, and sour gas processing systems compliant with NACE MR
0175 standards . It withstands the dual challenges of seawater
corrosion and high-pressure hydrocarbon environments.
- Marine Engineering: Fabricated into pumps, valves, and heat
exchangers for seawater cooling systems, where its resistance to
pitting and crevice corrosion outperforms conventional stainless
steels .
- Pollution Control: Utilized in flue gas desulfurization (FGD)
systems, where it resists the corrosive effects of wet scrubber
chemicals .
- Pharmaceuticals: Employed in equipment for sterile chemical
processing, leveraging its high purity and resistance to cleaning
agents.
Why Choose Hot Rolled Annealed Hastelloy C276 Round Bars?
Beyond its inherent material advantages, this product offers
practical benefits for industrial buyers:
- Cost-Efficiency: The hot rolled process reduces material waste
compared to cold drawing, while the annealing step eliminates the
need for secondary stress-relief treatments.
- Versatility: The 5-350mm diameter range covers applications from
small fasteners to large pressure vessel components.
- Longevity: In typical industrial environments, Hastelloy C276
components demonstrate 5-10 times longer service life than 316L
stainless steel, reducing replacement costs and downtime .
Whether for corrosive chemical handling, offshore operations, or
high-temperature processing, hot rolled annealed Hastelloy C276
round bars deliver reliable performance backed by decades of proven
industrial use. Their precise chemical composition and optimized
processing make them a benchmark material for critical engineering
applications.